The failure is:
Setting up bind9 (1:9.7.0.dfsg.P1-1) ...
* Stopping domain name service... bind9
/usr/sbin/postconf: fatal: open /etc/postfix/main.cf: No such file or directory
cp: `/etc/resolv.conf' and `/etc/resolv.conf' are the same file
run-parts: /etc/resolvconf/update-libc.d/postfix exited with return code 1
run-parts: /etc/resolvconf/update.d/libc exited with return code 1
invoke-rc.d: initscript bind9, action "restart" failed.
The failure is:
Setting up bind9 (1:9.7.0.dfsg.P1-1) ...
* Stopping domain name service... bind9
/usr/sbin/postconf: fatal: open /etc/postfix/ main.cf: No such file or directory
cp: `/etc/resolv.conf' and `/etc/resolv.conf' are the same file
run-parts: /etc/resolvconf /update- libc.d/ postfix exited with return code 1
run-parts: /etc/resolvconf /update. d/libc exited with return code 1
invoke-rc.d: initscript bind9, action "restart" failed.